3 Scientists Win Physics Nobel For Work On The Universe's Evolution

Oct 8, 2019
Originally published on October 8, 2019 12:02 pm
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DAVID GREENE, HOST:

Their discoveries have changed how we view our place in the universe, and now three scientists have been awarded the Nobel Prize in physics today for those accomplishments. Joining us to discuss the big picture - the really, really big picture - that is involved in this research is NPR science correspondent Geoff Brumfiel. Hi there, Geoff.

GEOFF BRUMFIEL, BYLINE: Good morning.

GREENE: OK, so who won the prize?

BRUMFIEL: Well, half the prize went to James Peebles of Princeton University for his work on the origins and makeup of the entire universe.

GREENE: Wow.

BRUMFIEL: And then the other half was shared between Michel Mayor of the University of Geneva and Didier Queloz of Geneva University (ph) and Cambridge University for their discovery of the first exoplanet orbiting a sun-like star.

GREENE: OK. Well, take us through what we need to know about this research and what it says about our place in the universe (laughter).

BRUMFIEL: Yeah. Well, why don't we start small here with a...

GREENE: OK. Got it.

BRUMFIEL: I mean relatively small, with the discovery of this planet.

GREENE: OK.

(LAUGHTER)

BRUMFIEL: So back in 1995, Mayor and Queloz were researchers, and they were looking at a star in the Milky Way called D51 Pegasi. And what they did was they monitored the star, and they were looking for a wobble. So basically, you know, a star like the sun obviously pulls on the Earth, but what you may not think about is the Earth pulls on the sun as well. And so...

GREENE: The sun actually wobbles?

BRUMFIEL: Yeah, it actually wobbles a little bit...

GREENE: OK.

BRUMFIEL: ...Because of the planets going around it. So they were monitoring the star, and they saw it wobble. There was another planet out there pulling on it. But this was not an Earth-sized planet; this was something more like the size of Jupiter. And it was orbiting really, really close to the star, far closer than anyone thought a Jupiter could exist. So this was the first of many hot Jupiters that scientists have since discovered, and that's really upended our understanding of planetary formation.

GREENE: Huh. And so that was half the prize announced today, right? What was the other half?

BRUMFIEL: The other half went to James Peebles, and he's cosmologist. This is a scientist who thinks about the very origins of the entire universe and how the universe will end. And of course, you can imagine this can veer pretty quickly into philosophy and sort of rampant speculation.

GREENE: I'm sure.

BRUMFIEL: That's not what Peebles did. What he did was he looked at a radiation left over from the very beginning of the universe, just after the Big Bang. It's called the cosmic microwave background, and it's sort of like this static - almost like a TV noise, if you have the channel tuned to the wrong station - that's just ubiquitous. But he took that radiation and he studied it, and he did calculations. And actually, by studying it, he was able to determine, together with many other researchers, that the stuff we see around us - planets, stars, things like that - only really make up about 5% of the universe.

GREENE: Really?

BRUMFIEL: The rest of it is dark matter, which is something that interacts only through gravity, and an even more mysterious thing called dark energy, and this is a force that appears to be pushing the entire universe apart. It's almost like an anti-gravity on very, very large scales.

GREENE: Dark energy does not sound like a good thing, necessarily.

BRUMFIEL: Not necessarily, but it's there.

GREENE: So the Nobel committee gave this award for new perspectives on our place in the universe? What is new? How has the perspective changed?

BRUMFIEL: I mean, I think these discoveries very much suggest, first of all, that we're not alone. Today we know there are literally thousands of planets out there; some may host life. But at the same time these discoveries also show we're very special. I mean, a lot of these planets are hot Jupiters that can never have life as we know it. And in terms of, you know, our place in the universe, we make up only 5% of it. So I hope everyone just feels a little more special today as a result of this Nobel Prize.

GREENE: Let's feel special. Geoff, thanks.

BRUMFIEL: Thank you.

GREENE: NPR science correspondent Geoff Brumfiel.

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